check if field has new value in buddypress xprofile

When a user updates their profile field “Country” or “City” with a new value, I want to be notified with only the field that has new value. Currently I’m using this but doesn’t tell which fields have been modified:
`add_action (‘xprofile_updated_profile’, ‘profile_change_notify’);
function profile_change_notify ($vars = array ())
{
$user = new WP_User ($vars);
wp_mail (‘myname@mydomain.com’, ‘Subject ( ‘ . $user->user_login . ‘ just updated the Profile )’, ‘Message Body goes here.’);
}`